CN112185694B

CN112185694B - Capacitor assembly

Info

Publication number: CN112185694B
Application number: CN202010625935.4A
Authority: CN
Inventors: 朴龙�; 李种晧; 申旴澈; 洪奇杓
Original assignee: Samsung Electro Mechanics Co Ltd
Current assignee: Samsung Electro Mechanics Co Ltd
Priority date: 2019-07-02
Filing date: 2020-07-01
Publication date: 2022-10-28
Anticipated expiration: 2040-07-01
Also published as: CN112185694A; US20210005391A1; KR20190116121A; CN216412888U; US11250992B2; CN212676102U; US20220037089A1; CN115512968A; US11626254B2

Abstract

The present invention provides a capacitor assembly comprising a body, the body comprising: a lamination part having first and second internal electrodes alternately stacked, the first and second internal electrodes being laminated along a first direction with a dielectric layer interposed therebetween; and first and second connection portions respectively provided on two opposite surfaces of the stacked portion in a second direction perpendicular to the first direction and respectively connected to the first and second internal electrodes. The first connection portion and the second connection portion each include: a metal layer provided on the laminated portion; a ceramic layer disposed on the metal layer; and an exposed portion penetrating the ceramic layer to contact the metal layer.

Description

Capacitor assembly

This application claims the benefit of priority of korean patent application No. 10-2019-0079455, filed in 2019 on 7/2 in the korean intellectual property office, the entire disclosure of which is incorporated herein by reference.

Technical Field

The present disclosure relates to a capacitor assembly.

Background

A multilayer ceramic capacitor (MLCC), a capacitor assembly, has a small size and a high capacitance, and can be easily mounted.

In general, when forming the external electrode in the MLCC, a paste including a conductive metal may be used, and a surface of the body on which the internal electrode is exposed may be impregnated in the paste.

However, the thickness of the external electrode formed by the dipping method may not be uniform, and the thickness of the external electrode may be excessively reduced on the corner of the body. In addition, when the plating layer is formed on the external electrode, the plating solution may penetrate into the main body, which may reduce the reliability of the MLCC.

In order to solve the above-mentioned problems, the external electrode may be divided into a primary external electrode and a secondary external electrode, and the primary external electrode may be formed by a transfer process or the like. However, when the above method is used, the contact area between the inner electrode and the outer electrode may be reduced as compared to when the general method is used, and thus, the resistance and ESR may be increased.

Disclosure of Invention

An aspect of the present disclosure is to provide a capacitor assembly having improved moisture-proof reliability.

Another aspect of the present disclosure is to provide a capacitor assembly having reduced ESR by improving electrode connectivity.

Another aspect of the present disclosure is to provide a capacitor assembly having improved contact performance that can prevent delamination.

According to an aspect of the present disclosure, a capacitor assembly includes a body including: a lamination part having first and second internal electrodes alternately stacked, the first and second internal electrodes being laminated along a first direction with a dielectric layer interposed therebetween; and first and second connection portions that are respectively provided on two opposite surfaces of the stacked portion in a second direction perpendicular to the first direction and are respectively connected to the first and second internal electrodes, and each of the first and second connection portions includes: a metal layer provided on the laminated portion; a ceramic layer disposed on the metal layer; and an exposed portion penetrating the ceramic layer to contact the metal layer.

According to another aspect of the present disclosure, a capacitor assembly includes a body including: a lamination part having first and second internal electrodes alternately stacked, the first and second internal electrodes being laminated along a first direction with a dielectric layer interposed therebetween; first and second metal layers respectively provided on two opposite surfaces of the laminated portion in a second direction perpendicular to the first direction and respectively connected to the first and second internal electrodes; first and second exposed portions disposed on central portions of outer surfaces of the first and second metal layers, respectively, to be connected to the first and second metal layers, respectively; and first and second ceramic layers disposed on remaining portions of the outer surfaces of the first and second metal layers, respectively, the remaining portions surrounding the central portion.

Drawings

The above and other aspects, features and advantages of the present disclosure will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

fig. 1 is a perspective view illustrating a capacitor assembly according to an exemplary embodiment of the present disclosure;

fig. 2 is a perspective view illustrating the main body shown in fig. 1;

fig. 3 is a perspective view illustrating the laminated part shown in fig. 1;

FIG. 4 is a sectional view taken along line I-I' of FIG. 1;

fig. 5A and 5B are sectional views taken along the X direction and the Y direction shown in fig. 1, fig. 5A being a sectional view showing a first internal electrode, and fig. 5B being a sectional view showing a second internal electrode;

fig. 6A, 6B, 7A, and 7B are diagrams illustrating a connection portion in which an exposed portion is formed;

fig. 8 to 11 are diagrams illustrating a process for forming a connection part of a capacitor assembly using a transfer method according to an exemplary embodiment of the present disclosure; and

fig. 12 is a diagram illustrating a process for forming external electrodes on connection parts of a capacitor assembly according to an exemplary embodiment of the present disclosure.

Detailed Description

Hereinafter, embodiments of the present disclosure will be described as follows with reference to the accompanying drawings.

These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It is to be understood that the various embodiments of the invention, although different, are not necessarily mutually exclusive. For example, structures, shapes, and dimensions described as examples in embodiments in the present disclosure may be implemented in another exemplary embodiment without departing from the spirit and scope of the present disclosure. For clarity of description, the shapes and sizes of elements in the drawings may be exaggerated, and the same elements will be denoted by the same reference numerals.

Some elements may be omitted or briefly shown for clarity of description, and thicknesses of elements may be exaggerated to clearly represent layers and regions. It will be understood that when an element is referred to as being "comprising" it can further comprise, but not exclude, other elements, unless otherwise indicated.

In the drawings, the X direction may be defined as a second direction, an L direction, or a length direction, the Y direction may be defined as a third direction, a W direction, or a width direction, and the Z direction may be defined as a first direction, a T direction, or a thickness direction.

In the following description, the capacitor assembly will be described in more detail with reference to fig. 1 to 5B.

The capacitor assembly 10 may include a body 100, the body 100 including a lamination part 110 and first and

second connection parts

141 and 142, first and second

internal electrodes

121 and 122 opposite to each other in the lamination part 110 being laminated along a first direction (Z direction) with a dielectric layer 111 interposed between the first and second

internal electrodes

121 and 122, the first and

second connection parts

141 and 142 being respectively disposed on both surfaces of the lamination part in a second direction (X direction) perpendicular to the first direction and connected to the first and second

internal electrodes

121 and 122, respectively, and the first connection part 141 including a metal layer 141a disposed on the lamination part 110, a ceramic layer 141b disposed on the metal layer 141a, and an exposed part 143 penetrating the ceramic layer 141b and contacting the metal layer 141a, the second connection part 142 including a metal layer 142a disposed on the lamination part 110, a ceramic layer 142b disposed on the metal layer 142a, and an exposed part 144 penetrating the ceramic layer 142b and contacting the metal layer 142a.

In an exemplary embodiment of the present disclosure, the body 100 may include a lamination part 110 and first and

second connection parts

141 and 142.

The shape of the body 100 may not be limited to any particular shape, and the body 100 may have a hexahedral shape or a hexahedral-like shape. The body 100 may not have an exact hexahedral shape including straight lines but may have a substantially hexahedral shape due to shrinkage of the ceramic powder included in the body 100 during the sintering process. The body 100 may have first and second surfaces 1 and 2 opposite to each other in a thickness direction (Z direction), third and fourth surfaces 3 and 4 connected to the first and second surfaces 1 and 2 and opposite to each other in a length direction (X direction), and fifth and sixth surfaces 5 and 6 connected to the first and second surfaces 1 and 2 and the third and fourth surfaces 3 and 4 and opposite to each other in a width direction (Y direction).

In the exemplary embodiment of the present disclosure, in the stacked part 110, the dielectric layer 111 and the first and second

internal electrodes

121 and 122 may be alternately stacked, and the dielectric layer 111 and the first and second

internal electrodes

121 and 122 may be stacked along the first direction. The plurality of dielectric layers 111 included in the lamination part 110 may be in a sintered state, and the dielectric layers may be integrated such that it may be difficult to identify a boundary between adjacent dielectric layers without using a Scanning Electron Microscope (SEM).

In the exemplary embodiment of the present disclosure, the material of the dielectric layer 111 may not be limited to any particular material as long as sufficient capacitance can be obtained. For example, the dielectric layer 111 may be formed using a barium titanate material, a perovskite material compound having lead (Pb), a strontium titanate material, or the like.

Barium titanate (BaTiO) including various ceramic additives, organic solvents, coupling agents, dispersing agents, etc. may be used according to the intended purpose ₃ ) Powder, etc. as the material of the dielectric layer 111.

The stacked portion may be formed by alternately stacking, along the thickness direction (Z direction), ceramic green sheets on which the first internal electrodes 121 are printed and ceramic green sheets on which the second internal electrodes 122 are printed.

In an exemplary embodiment of the present disclosure, the plurality of

internal electrodes

121 and 122 may be opposite to each other with the dielectric layer 111 interposed therebetween. The

internal electrodes

121 and 122 may include first and second

internal electrodes

121 and 122 alternately disposed and opposite to each other with the dielectric layer 111 interposed between the first and second

internal electrodes

121 and 122.

The first internal electrode 121 may be exposed to only one surface of the stacked part 110 in the second direction (X direction), and a portion exposed to the one surface in the second direction (X direction) may be connected to the metal layer 141a of the first connection part. The second internal electrode 122 may be exposed to the other surface of the stacked part 110 in the second direction (X direction), and a portion exposed to the other surface in the second direction (X direction) may be connected to the metal layer 142a of the second connection part. The first and second

internal electrodes

121 and 122 may be electrically isolated from each other by the dielectric layer 111 interposed therebetween.

The materials of the first and second

internal electrodes

121 and 122 are not limited to any particular materials. For example, the first and second

internal electrodes

121 and 122 may be formed using, for example, a conductive paste including one or more materials among silver (Ag), palladium (Pd), gold (Au), platinum (Pt), nickel (Ni), tin (Sn), copper (Cu), tungsten (W), titanium (Ti), and an alloy thereof. As a method of printing the conductive paste, a screen printing method, a gravure printing method, or the like may be used, but the printing method is not limited thereto.

The average thickness of the first and second

internal electrodes

121 and 122 may be less than or equal to 0.4 μm. The average thickness of the first and second

internal electrodes

121 and 122 may be an average of thicknesses measured in different five locations of the sintered internal electrode. The lower limit of the average thickness of the first and second

internal electrodes

121 and 122 is not limited to any particular thickness, and may be, for example, greater than or equal to 0.01 μm.

In an exemplary embodiment of the present disclosure, the first connection part 141 may include a metal layer 141a disposed on the lamination part 110, a ceramic layer 141b disposed on the metal layer 141a, and an exposed part 143 penetrating the ceramic layer 141b and contacting the metal layer 141a, and the second connection part 142 may include a metal layer 142a disposed on the lamination part 110, a ceramic layer 142b disposed on the metal layer 142a, and an exposed part 144 penetrating the ceramic layer 142b and contacting the metal layer 142a.

The

metal layers

141a and 142a may be disposed on one surface and the other surface of the stacked part 110 in the second direction (X direction), respectively, and may be electrically connected to the first and second

internal electrodes

121 and 122, respectively.

The

metal layers

141a and 142a may include a metal material having high conductivity, and in order to increase electrical connectivity with the first and second

internal electrodes

121 and 122, respectively, the

metal layers

141a and 142a may include the same metal as that included in the first and second

internal electrodes

121 and 122. For example, the

metal layers

141a and 142a may include one or more of silver (Ag), palladium (Pd), gold (Au), platinum (Pt), nickel (Ni), tin (Sn), copper (Cu), tungsten (W), titanium (Ti), and alloys thereof.

The

metal layers

141a and 142a may be provided in the form of sintered electrodes, and may be sintered simultaneously with the body 100. In this case, the

metal layers

141a and 142a before sintering may include metal particles and an organic material such as a binder, and may be transferred on the body 100, and the organic material and the like may be removed after the sintering process.

For example, the thickness ta of the metal layer may be 1 μm to 10 μm. The thickness ta of the metal layer may refer to a length of the metal layer taken along the second direction (X direction). The thickness ta of the metal layer may be greater than or equal to 1.0 μm, greater than or equal to 1.5 μm, or greater than or equal to 2.0 μm, and may be less than or equal to 10.0 μm, less than or equal to 9.5 μm, less than or equal to 9.0 μm, less than or equal to 8.5 μm, less than or equal to 8.0 μm, less than or equal to 7.5 μm, or less than or equal to 7.0 μm. However, the thickness of the metal layer is not limited thereto. When the thickness of the metal layer satisfies the above thickness range, the connectivity with the inner electrode may be ensured, and the conductivity with the outer electrode may be ensured.

The

ceramic layers

141b and 142b may be disposed on the

metal layers

141a and 142a, and may improve sealing performance, so that penetration of moisture or plating solution into the body 100 may be significantly reduced. The

ceramic layers

141b and 142b may be configured not to cover the surfaces of the

metal layers

141a and 142a in the first direction (Z direction) and the surfaces in the third direction (Y direction).

The

ceramic layers

141b and 142b may be formed using a ceramic material such as barium titanate or the like. In this case, the

ceramic layers

141b and 142b may include the same ceramic material as that included in the dielectric layer 111, or may be formed using the same material as that of the dielectric layer 111.

The

ceramic layers

141b and 142b may be formed on the

metal layers

141a and 142a through a transfer process, and then a sintering process may be performed. It may be preferable that the

ceramic layers

141b and 142b have high adhesion for a transfer process before sintering, and thus, the

ceramic layers

141b and 142b may include a relatively large amount of organic materials (such as a binder, etc.). In this case, since the organic material may partially remain after the sintering process, the

ceramic layers

141b and 142b may include a larger amount of the organic material than the organic material included in the dielectric layer 111.

For example, the thickness tb of the ceramic layer may be 3 μm to 15 μm. The thickness tb of the ceramic layer may refer to a length of the ceramic layer taken along the second direction (X direction). The thickness tb of the ceramic layer may be greater than or equal to 3.0 μm, greater than or equal to 3.5 μm, greater than or equal to 4.0 μm, greater than or equal to 4.5 μm, or greater than or equal to 5.0 μm, and may be less than or equal to 15.0 μm, less than or equal to 14.5 μm, less than or equal to 14.0 μm, less than or equal to 13.5 μm, less than or equal to 13.0 μm, less than or equal to 12.5 μm, less than or equal to 12.0 μm, less than or equal to 11.5 μm, less than or equal to 11.0 μm, less than or equal to 10.5 μm, or less than or equal to 10.0 μm. However, examples of the thickness are not limited thereto. When the thickness of the ceramic layer satisfies the above range, moisture-proof reliability can be ensured, and the strength of the capacitor assembly can be increased.

The exposed

portions

143 and 144 may be disposed in the

ceramic layers

141b and 142b, respectively, and may have shapes penetrating the

ceramic layers

141b and 142b, respectively. The configuration of the exposed portion 143 penetrating the ceramic layer 141b may mean that one side surface of the exposed portion 143 may be in contact with the metal layer 141a and the other side surface of the exposed portion 143 may be exposed to the outside of the body 100, and the configuration of the exposed portion 144 penetrating the ceramic layer 142b may mean that one side surface of the exposed portion 144 may be in contact with the metal layer 142a and the other side surface of the exposed portion 144 may be exposed to the outside of the body 100. In addition, when the exposed part 143 is configured to penetrate the ceramic layer 141b, one side surface of the exposed part 143 may contact the metal layer 141a and the other side surface of the exposed part 143 may contact the external electrode 151, and when the exposed part 144 is configured to penetrate the ceramic layer 142b, one side surface of the exposed part 144 may contact the metal layer 142a and the other side surface of the exposed part 144 may contact the external electrode 152.

Fig. 2, 4, 5A, and 5B are diagrams illustrating the body 100 in which the exposed

portions

143 and 144 penetrating the ceramic layers 141B and 142B and contacting the

metal layers

141a and 142a are formed and the capacitor assembly 10 including the body 100. Referring to fig. 2, 4, and 5A and 5B, the exposed portion 143 disposed in the ceramic layer 141B may penetrate the ceramic layer 141B and may be in contact with the metal layer 141a, and the exposed portion 144 disposed in the ceramic layer 142B may penetrate the ceramic layer 142B and may be in contact with the metal layer 142a. In the configuration, the exposed portion 143 may serve as a conductive path connecting the metal layer 141a connected to the first inner electrode 121 to the outer electrode 151, and the exposed portion 144 may serve as a conductive path connecting the metal layer 142a connected to the second inner electrode 122 to the outer electrode 152. Therefore, compared to a configuration in which only the metal layer 141a and the outer electrode 151 are connected to each other and the metal layer 142a and the outer electrode 152 are connected to each other, a contact area between the inner and outer electrodes may be increased and ESR may be reduced.

In an exemplary embodiment of the present disclosure, a ratio (a/B) of an area a of the exposed

portions

143 and 144 contacting the

metal layers

141a and 142a to an area B of the

metal layers

141a and 142a may be less than or equal to 0.7. The areas B of the

metal layers

141a and 142a and the areas a of the exposed

portions

143 and 144 in contact with the

metal layers

141a and 142a may be measured with reference to sections (Y-Z sections) taken along the first and third directions. For example, as in fig. 2, the area of the third or fourth surface of the body 100 may be the area B of the

metal layers

141a and 142a, and the area a of the exposed

portions

143 and 144 may be the area of the portion exposed to the third or fourth surface of the body 100. The ratio (a/B) of the area a of the exposed

portions

143 and 144 in contact with the

metal layers

141a and 142a to the area B of the

metal layers

141a and 142a may be less than or equal to 0.7, less than or equal to 0.6, or less than or equal to 0.5, and the lower limit may not be limited to any particular value. For example, the lower limit may be greater than or equal to 0.01. When the ratio (a/B) satisfies the above range, improved moisture-proof reliability can be achieved, and ESR can be reduced.

Fig. 6A and 6B show examples of the exposed portion. Referring to fig. 6A, the exposed portion 143 may have a rectangular shape, and the ceramic layer 141b may be disposed around the exposed portion 143. Further, referring to fig. 6B, two or more exposed portions 243 (having a rectangular shape) may be provided, and a ceramic layer 241B may be provided around the two or more exposed portions 243.

Fig. 7A and 7B show another example of the exposure portion. Referring to fig. 7A, the exposure portion 343 may have a circular shape (or an elliptical shape), and the ceramic layer 341b may be disposed around the exposure portion 343. Further, referring to fig. 7B, two or more exposed portions 443 (having a circular shape or an elliptical shape) may be disposed, and the ceramic layer 441B may be disposed around the two or more exposed portions 443.

The shape and number of the exposed portions described with reference to fig. 6A, 6B, 7A, and 7B may not be limited to the examples shown in fig. 6A, 6B, 7A, and 7B, and may be changed.

In an exemplary embodiment of the present disclosure, the exposed

portions

143 and 144 may include a metal material having high conductivity, and in order to improve electrical connectivity with the

metal layers

141a and 142a, the exposed

portions

143 and 144 may include the same metal as that included in the

metal layers

141a and 142a. For example, the exposed

portions

143 and 144 may include one or more of silver (Ag), palladium (Pd), gold (Au), platinum (Pt), nickel (Ni), tin (Sn), copper (Cu), tungsten (W), titanium (Ti), and alloys thereof.

The exposed

portions

143 and 144 may be provided in the form of sintered electrodes, and may be sintered simultaneously with the body 100. In this case, the exposed

portions

143 and 144 before sintering may include metal particles and an organic material such as a binder, and may be transferred on the

metal layers

141a and 142a. After the sintering process, organic materials and the like may be removed.

In an exemplary embodiment of the present disclosure, the first connection part 141 and the second connection part 142 may be formed by a method of transferring a sheet. The method of transferring the sheet is not limited to any particular method. For example, a metal layer having a sheet form and a ceramic layer having a sheet form including an exposed portion may be transferred on the body, and the sheet may have a uniform thickness. Accordingly, a ratio of the minimum value to the maximum value in the thickness of the connection part 141 may be 0.9 to 1.0, and a ratio of the minimum value to the maximum value in the thickness of the connection part 142 may be 0.9 to 1.0. The thickness of each of the

connection parts

141 and 142 may refer to a length of each of the

connection parts

141 and 142 taken along the second direction (X direction).

According to another exemplary embodiment of the present disclosure, each of the corners of the body 100 on the section taken along the first and second directions may have a rounded shape. By having a rounded shape, the

external electrodes

151 and 152 may have a reduced and uniform thickness.

When each of the corners of the main body has an angled shape, a peeling (chipping) defect of the corners, cracking caused by collision between sheets, may occur during a process of manufacturing the MLCC, which may cause an external defect and may deteriorate moisture-proof reliability. In general, to solve this problem, the corners of the body may be ground to have a rounded shape to prevent the thickness of the external electrodes on the corners from being reduced and to prevent peeling defects.

However, by grinding the corners of the body, exposure of the inner electrodes or other problems may occur, so that it may be difficult to ensure a sufficiently rounded shape on each of the corners of the body in a general capacitor assembly. Further, in order to prevent the exposure of the internal electrode, when the thickness of the protective part 112 is increased, the capacitance per unit volume of the capacitor assembly may be decreased.

In an exemplary embodiment of the present disclosure, by providing the first and

second connection parts

141 and 142 on both surfaces of the lamination part 110 in the second direction (X direction), a sufficiently rounded shape may be formed on the corner of the body 100. Therefore, the thickness of the external electrode on each corner can be prevented from being reduced without reducing the capacitance per unit volume, and the peeling defect can be prevented.

In an exemplary embodiment of the present disclosure, the lamination part 110 may include: a capacitance forming part defining a capacitance of the capacitor assembly 10 and including first and second

internal electrodes

121 and 122 opposite to each other and a dielectric layer 111 interposed between the first and second

internal electrodes

121 and 122; and a protection part 112 disposed on upper and lower portions of the capacitance forming part.

The upper and lower protective portions may have the same composition as that of the dielectric layer 111, and may be formed by stacking one or more dielectric layers, which do not include the internal electrodes, in the upper portion of the uppermost internal electrode and the lower portion of the lowermost internal electrode of the body 100.

The upper and lower

protective parts

112 and 112 may prevent damage to the inner electrode caused by physical stress or chemical stress.

For example, the thickness tp of each of the upper protective portion 112 and the lower protective portion 112 may be less than or equal to 25 μm. The thickness tp of each of the upper protective portion 112 and the lower protective portion 112 may be less than or equal to 25 μm, less than or equal to 24 μm, less than or equal to 23 μm, less than or equal to 22 μm, less than or equal to 21 μm, or less than or equal to 20 μm. In the example embodiment of the present disclosure, by providing the

connection parts

141 and 142 on the lamination part 110, a sufficiently rounded shape may be formed on the corner of the body 100, and thus, by significantly reducing the thickness tp of each of the upper and lower protection parts, the capacitance per unit volume of the capacitor assembly 10 may be improved.

For example, even when the thickness tp is less than or equal to 20 μm, a sufficiently rounded shape can be formed, and the internal electrodes can be protected. Therefore, the capacitance per unit volume of the capacitor assembly can be improved. Therefore, when the thickness tp is less than or equal to 20 μm, the above effect can be more prominent.

The lower limit of the thickness tp is not limited to any particular size, and may be selected in consideration of the radius of curvature R1 of the corner portion of the body 100 on the section taken along the first and second directions. For example, the lower limit of the thickness tp may be greater than or equal to 5 μm.

The thickness tp of each of the upper and

lower guard portions

112 and 112 may refer to a length of each of the upper and

lower guard portions

112 and 112 taken along the first direction (Z direction).

Referring to fig. 4, when the thickness of each of the upper and

lower sheathing parts

112 and 112 is defined as tp and the radius of curvature of each of the corners of the body 100 on a section taken along the first and second directions (a Z-X section, i.e., an L-T section) is defined as R1, R1/tp may be greater than or equal to 0.3 and less than or equal to 1.4.

When R1/tp is less than 0.3, a sufficiently rounded shape may not be formed, so that a peeling defect may occur, or the thickness of the external electrode on the corner may be reduced.

When R1/tp is greater than 1.4, a short circuit caused by exposure of the internal electrode may occur, or it may be difficult to form the external electrode. The short circuit caused by the exposure of the internal electrode may refer to a phenomenon in which: as the corners of the body 100 are ground, the first internal electrode 121 may be exposed to the surface on which the second external electrode 152 is disposed and may be connected to the second external electrode 152, or the second internal electrode 122 may be exposed to the surface on which the first external electrode 151 is disposed and may be connected to the first external electrode 151.

R1/tp may be greater than 1.0 and less than or equal to 1.4.

When the

connection parts

141 and 142 are not provided and R1/tp is controlled to be more than 1.0, short circuits caused by exposure of the internal electrodes are highly likely to occur. However, when the

connection parts

141 and 142 are provided as in the exemplary embodiment, even when R1/tp is controlled to be greater than 1.0 and less than or equal to 1.4, the possibility of short circuits caused by exposure of the inner electrodes may be significantly reduced.

A rounded shape of each of the corners of the body 100 in a section taken along the first and second directions may be formed on the

connection parts

141 and 142, and may extend to a portion of the lamination part 110, as shown in fig. 4 and 5A and 5B.

In exemplary embodiments of the present disclosure, the first and

second edge portions

131 and 132 may be disposed on both surfaces of the laminated portion 110 in a third direction (Y direction) perpendicular to the first and second directions, respectively.

In a general capacitor assembly, the area of the dielectric layer may be configured to be larger than that of the inner electrode, and the edge region may be formed on the remaining outer circumferential portion except for the portion of the inner electrode connected to the outer electrode. In this case, however, when several tens to several hundreds of dielectric layers are stacked, the dielectric layers may be elongated to fill the step difference, and thus, the internal electrodes may be bent. When the inner electrode is bent, breakdown voltage (BDV) performance may be lowered in the corresponding portion.

Therefore, in the capacitor assembly in the exemplary embodiment, a step difference caused by the internal electrodes may be prevented by removing edge regions on both surfaces of the stacked part 110 in the third direction, and the internal electrodes may be prevented from being bent. Therefore, the problem of the degradation of breakdown voltage (BDV) performance can be prevented, thereby improving the reliability of the capacitor assembly.

In addition, by providing the first margin portion 131 and the second margin portion 132 on both surfaces of the stacked portion 110 in the third direction, the internal electrode can be protected. Further, since the first and

second edge portions

131 and 132 are separately formed, it may not be necessary to consider manufacturing errors (such as misalignment of the internal electrodes). Therefore, when the thickness Wm of each of the first and

second margin portions

131 and 132 can be configured to be smaller than that of the margin region in the general capacitor assembly, the capacitance per unit volume of the capacitor assembly can be improved.

Accordingly, when the body 100 includes the first and

second margin parts

131 and 132, the first internal electrode 121 may be exposed to both surfaces of the stacked part 110 in the third direction and one surface of the stacked part 110 in the second direction, and a portion exposed to the one surface in the second direction may be connected to the first connection part 141. Further, the second internal electrode 122 may be exposed to both surfaces of the stacked part 110 in the third direction and the other surface of the stacked part 110 in the second direction, and a portion exposed to the other surface in the second direction may be connected to the second connection part 142.

The first and

second edge portions

131 and 132 may be formed using an insulating material, and may be formed using a ceramic material such as barium titanate. In this case, the first and

second edge portions

131 and 132 may include the same ceramic material as that included in the dielectric layer 111, or may be formed using the same material as that included in the dielectric layer 111.

The method of forming the first and

second edge portions

131 and 132 may not be limited to any particular method. For example, the first and

second edge portions

131 and 132 may be formed by coating a slurry including a ceramic or laminating a dielectric sheet on both surfaces of the laminated portion in the third direction.

The first and

second edge portions

131 and 132 may also be formed by transferring the dielectric sheet using the above-described transfer process. Accordingly, each of the first and

second edge portions

131 and 132 may have a uniform thickness. When the thickness of each of the first and

second edge portions

131 and 132 is defined as Wm, a ratio of the minimum value to the maximum value of the thickness Wm may be 0.9 to 1.0.

When the first and

second edge portions

131 and 132 are formed by the transfer dielectric sheet, it may be preferable that the first and

second edge portions

131 and 132 have a high adhesion force for a transfer process before sintering. For this, the first and

second edge portions

131 and 132 may include a relatively large amount of organic material (such as an adhesive). In this case, since the organic material may partially remain after the sintering process, the first and

second edge portions

131 and 132 may include an amount of the organic material greater than an amount of the organic material included in the dielectric layer 111.

The thickness Wm of each of the first and

second edge portions

131 and 132 may not be limited to any particular size. In the exemplary embodiment of the present disclosure, since a sufficiently rounded shape may be formed on the corner of the body 100 by providing the

connection parts

141 and 142 on the lamination part 110, the capacitance per unit volume of the capacitor assembly may be improved by significantly reducing the thickness Wm. For example, in the exemplary embodiment of the present disclosure, even when the thickness Wm is less than or equal to 15 μm, a sufficiently rounded shape may be formed and the

internal electrodes

121 and 122 may also be protected, thereby improving the capacitance per unit volume of the capacitor assembly.

The lower limit of the thickness Wm may not be limited to any particular size, and may be selected in consideration of a radius of curvature R2 of a corner portion of the body on a section (X-Y section, i.e., L-W section) taken along the second and third directions. For example, the thickness Wm may be greater than or equal to 5 μm. The thickness Wm of each of the first and

second edge portions

131 and 132 may refer to a length of each of the first and

second edge portions

131 and 132 taken along the third direction (Y direction).

Referring to fig. 5A and 5B, when a thickness of each of the first and

second rim portions

131 and 132 is defined as Wm, and a radius of curvature of a corner portion of the main body in a section taken along the second and third directions (an X-Y section, i.e., an L-W section) is defined as R2, R2/Wm may be greater than or equal to 0.3 and less than or equal to 1.4. When R2/Wm is less than 0.3, a sufficiently rounded shape may not be formed, so that a peeling defect may occur or the thickness of the external electrode on the corner may be reduced. When R2/Wm exceeds 1.4, a short circuit caused by exposure of the internal electrode may occur, or it may be difficult to form the external electrode. The short circuit caused by the exposure of the internal electrode may refer to a phenomenon in which: as the corners of the body are ground, the first internal electrode 121 may be exposed to the surface on which the second external electrode 152 is disposed and may be connected to the second external electrode 152, or the second internal electrode 122 may be exposed to the surface on which the first external electrode 151 is disposed and may be connected to the first external electrode 151.

R2/Wm may be greater than 1.0 and less than or equal to 1.4.

When the

connection parts

141 and 142 are not provided and R2/Wm is controlled to be more than 1.0, short circuits caused by exposure of the internal electrodes are highly likely to occur. However, when the

connection parts

141 and 142 are provided as in the exemplary embodiment of the present disclosure, even when R2/Wm is controlled to be greater than 1.0 and less than or equal to 1.4, the possibility of short circuit caused by exposure of the inner electrodes may be significantly reduced.

In order to easily perform the grinding process, the radius of curvature R2 of the corner of the body 100 on the section taken along the second and third directions may be configured to be the same as the radius of curvature R1 of the corner of the body 100 on the section taken along the first and second directions, but exemplary embodiments thereof are not limited thereto. The corners of the body 100 may be ground so that R2 and R1 may be configured differently.

Since the first and

second connection parts

141 and 142 may be formed using a transfer process after the first and

second edge parts

131 and 132 are formed on the laminated part 110, the first connection part 141 may be disposed to cover one surfaces of the first and

second edge parts

131 and 132 in the second direction (X direction), and the second connection part 142 may be disposed to cover the other surfaces of the first and

second edge parts

131 and 132 in the second direction (X direction).

The first connection portion 141 may be disposed in one surface of the laminated portion 110 and the first and

second edge portions

131 and 132 in the second direction (X direction), and the second connection portion 142 may be disposed in the other surface of the laminated portion 110 and the first and

second edge portions

131 and 132 in the second direction (X direction). Accordingly, the first connection part 141 may not extend to both surfaces of the laminated part 110 in the first direction (Z direction), and may not extend to both surfaces of the first and

second edge parts

131 and 132 in the third direction (Y direction).

The first and second

external electrodes

151 and 152 may be disposed on the first and

second connection parts

141 and 142, respectively. The first external electrode 151 may be electrically connected to the first internal electrode 121 through the metal layer 141a of the first connection part 141 and the exposed part 143, and the second external electrode 152 may be electrically connected to the second internal electrode 122 through the metal layer 142a of the second connection part 142 and the exposed part 144.

The first and second

external electrodes

151 and 152 may extend to both surfaces of the first and

second connection parts

141 and 142 in the first direction (Z direction), and the

metal layers

141a and 142a of the first and

second connection parts

141 and 142 may be exposed to the surfaces of the first and

second connection parts

141 and 142 in the first direction (Z direction) and may be connected to the first and second

external electrodes

151 and 152, respectively. The first and second

external electrodes

151 and 152 may further extend to both surfaces of the first and

second connection parts

141 and 142 in the third direction (Y direction), and the

metal layers

141a and 142a of the first and

second connection parts

141 and 142 may be further exposed to the surfaces of the first and

second connection parts

141 and 142 in the third direction (Y direction) and may be connected to the first and second

external electrodes

151 and 152, respectively.

The first and second

external electrodes

151 and 152 may extend to a portion of the first surface 1 and a portion of the second surface 2 of the body 100. The first and second

external electrodes

151 and 152 may also extend to a portion of the fifth surface 5 and a portion of the sixth surface 6 of the body 100.

The method of forming the first and second

external electrodes

151 and 152 may not be limited to any particular method. For example, the first and second

external electrodes

151 and 152 may be formed by dipping the body 100 in a paste including conductive metal and glass, or by transferring a dry film formed by drying the metal paste on the first and second connection portions.

In the exemplary embodiment of the present disclosure, since each of the corners of the body 100 has a rounded shape, even when the external electrodes are formed using the dipping process, a phenomenon in which the thickness of each of the

external electrodes

151 and 152 on the corners of the body 100 is reduced may be prevented.

In addition, when the external electrode is formed through a transfer process using the above dry film, the external electrode may have a uniform thickness.

Accordingly, when the thickness of each of the

outer electrodes

151 and 152 is defined as tc, the ratio of the minimum value to the maximum value of the thickness tc may be 0.8 to 1.0.

In an exemplary embodiment of the present disclosure, the thickness of each of the

external electrodes

151 and 152 may be in a range of 5 μm to 25 μm. For example, the thickness of each of the

external electrodes

151 and 152 may be greater than or equal to 5 μm, greater than or equal to 6 μm, greater than or equal to 7 μm, greater than or equal to 8 μm, greater than or equal to 9 μm, or greater than or equal to 10 μm, and may be less than or equal to 25 μm, less than or equal to 24 μm, less than or equal to 23 μm, less than or equal to 22 μm, less than or equal to 21 μm, or less than or equal to 20 μm. However, examples of the thickness are not limited thereto. When the thickness of each of the

outer electrodes

151 and 152 satisfies the above range, the capacitor assembly may have improved mounting performance and conductivity, and may have a reduced size.

In an exemplary embodiment of the present disclosure, the

outer electrodes

151 and 152 may include one or more of silver (Ag), palladium (Pd), gold (Au), platinum (Pt), nickel (Ni), tin (Sn), copper (Cu), tungsten (W), titanium (Ti), and an alloy thereof. When the

external electrodes

151 and 152 include nickel among the above elements, the connectivity of the metal layers electrically connected to the first and second

external electrodes

151 and 152 with the first and second connection parts may be improved, and the conductivity may be improved.

In order to improve the mounting performance with the substrate, plating layers may be formed on the first and second

external electrodes

151 and 152. For example, the plating layer may be implemented as Ni plating or Sn plating, and the Ni plating and the Sn plating may be sequentially formed on the external electrode. Alternatively, the first and second

external electrodes

151 and 152 may include a plurality of Ni plating layers and/or a plurality of Sn plating layers.

Fig. 8 to 11 are diagrams illustrating a process of forming the connection part 141 of the capacitor assembly through a transfer process according to an exemplary embodiment of the present disclosure.

As shown in fig. 8, in the process of transferring the metal layer 141a, the metal layer sheet 140a may be disposed on the support stage 300, and the lamination part 110 may be pressed to the metal layer sheet 140a so that the metal layer 141a may be adhered to the surface of the lamination part 110. The metal layer 140a that has not been sintered may include components such as a binder, an organic solvent, and the like.

As shown in fig. 9, a ceramic layer sheet 140b may be disposed on the support table 300, and the lamination portion 110 may be pressed to the ceramic layer sheet 140b so that the ceramic layer 141b may be adhered to the surface of the metal layer 141a. The ceramic plies 140b that have not been sintered may include components such as binders, organic solvents, and the like.

The same process may be performed on the other surface opposite to the surface on which the metal layer 141a and the ceramic layer 141b are disposed to form the metal layer 142a and the ceramic layer 142b, thereby manufacturing the body 100 as shown in fig. 11.

Each of the corners of the body may be processed to have a rounded shape by performing a grinding process, and the

external electrodes

151 and 152 may be formed by dipping the ground body 100 into the conductive paste 400, as shown in fig. 12, thereby manufacturing the capacitor assembly 10.

As shown in fig. 10, the first connection portion 141 may also be formed by laminating both the ceramic layer sheet 140b and the metal layer sheet 140a on the support table 300 and performing a single transfer process, instead of separately transferring the metal layer and the ceramic layer.

According to the foregoing exemplary embodiments of the present disclosure, by providing the connection portion on the lamination portion, the capacitance per unit volume of the capacitor assembly can be improved, and the moisture-proof reliability can be improved.

Further, each of the corners of the body may have a substantially rounded shape, and when each of the corners of the body has a substantially rounded shape, each of the external electrodes may have a uniform and reduced thickness.

In addition, by improving the electrode connectivity between the inner electrode and the outer electrode, a capacitor assembly having reduced ESR may be provided.

In addition, by improving the contact performance between the external electrode and the connection part, delamination in the capacitor assembly can be prevented.

While exemplary embodiments have been shown and described above, it will be apparent to those skilled in the art that modifications and variations can be made without departing from the scope of the invention defined by the appended claims.

Claims

1. A capacitor assembly, comprising:

a body, comprising:

a lamination part including first and second internal electrodes alternately stacked, the first and second internal electrodes being laminated along a first direction with a dielectric layer interposed therebetween; and

first and second connection portions that are respectively provided on two opposite surfaces of the laminated portion in a second direction perpendicular to the first direction and are respectively connected to the first and second internal electrodes,

wherein the first connecting portion and the second connecting portion each include: a metal layer provided on the laminated portion; a ceramic layer disposed on the metal layer; and an exposed portion penetrating the ceramic layer to be in contact with the metal layer,

wherein the metal layer comprises one or more selected from the group consisting of silver, palladium, gold, platinum, nickel, tin, copper, tungsten, titanium, and alloys thereof, and

wherein the ceramic layer is provided so as not to cover a surface of the metal layer in the first direction.

2. The capacitor assembly according to claim 1, wherein an average thickness of the first and second internal electrodes is less than or equal to 0.4 μ ι η.

3. The capacitor assembly of claim 1, wherein the thickness of each metal layer is in a range of 1 μ ι η to 10 μ ι η.

4. The capacitor assembly according to claim 1, wherein the thickness of each ceramic layer is in a range of 3 μ ι η to 15 μ ι η.

5. The capacitor assembly according to claim 1, wherein a ratio of an area of each exposed portion in contact with the metal layer to an area of each metal layer is less than or equal to 0.7.

6. The capacitor assembly according to claim 1, wherein a ratio of a minimum value to a maximum value of a thickness of each of the first and second connection portions is 0.9 to 1.0.

7. The capacitor assembly according to claim 1 wherein each of the corners of the body has a rounded shape.

8. The capacitor assembly according to claim 1, wherein the laminated portion comprises: a capacitance forming part defining a capacitance of the capacitor assembly and including the first and second internal electrodes opposite to each other and the dielectric layer interposed therebetween; and an upper protection part and a lower protection part respectively disposed on an upper portion and a lower portion of the capacitance forming part.

9. The capacitor assembly according to claim 8, wherein when a thickness of each of the upper and lower protective portions is defined as tp, and a radius of curvature of each of corner portions of the main body on a cross section taken along the first and second directions is defined as R1, R1/tp is greater than or equal to 0.3 and less than or equal to 1.4.

10. The capacitor assembly according to claim 9, wherein a thickness tp of each of the upper and lower protective portions is less than or equal to 25 μ ι η.

11. The capacitor assembly of claim 1 wherein the body further comprises:

first and second edge portions provided on two opposite surfaces of the laminated portion in a third direction perpendicular to the first and second directions, respectively.

12. The capacitor assembly according to claim 11, wherein the first internal electrode is exposed to one surface of the laminated portion in the second direction and both surfaces of the laminated portion in the third direction, the second internal electrode is exposed to the other surface of the laminated portion in the second direction and both surfaces of the laminated portion in the third direction,

wherein portions of both surfaces of the first and second internal electrodes in the third direction of the stacked portion that are exposed are covered by the first and second edge portions, respectively.

13. The capacitor assembly according to claim 11, wherein when a thickness of each of the first edge portion and the second edge portion is defined as Wm, and a radius of curvature of each of corners of the body on a cross section taken along the second direction and the third direction is defined as R2, R2/Wm is greater than or equal to 0.3 and less than or equal to 1.4.

14. The capacitor assembly according to claim 13, wherein a thickness Wm of each of the first and second edge portions is less than or equal to 15 μ ι η.

15. The capacitor assembly of claim 1, further comprising:

first and second external electrodes disposed on the first and second connection parts, respectively.

16. The capacitor assembly according to claim 15, wherein a ratio of a minimum value to a maximum value of a thickness of each of the first and second external electrodes is 0.8 to 1.0.

17. A capacitor assembly, comprising:

a body, comprising:

a lamination part including first and second internal electrodes alternately stacked, the first and second internal electrodes being laminated along a first direction with a dielectric layer interposed therebetween;

first and second metal layers respectively provided on two opposite surfaces of the laminated portion in a second direction perpendicular to the first direction and respectively connected to the first and second internal electrodes;

first and second exposed portions disposed on central portions of outer surfaces of the first and second metal layers, respectively, to be connected to the first and second metal layers, respectively; and

a first ceramic layer and a second ceramic layer disposed on a remaining portion of the outer surfaces of the first metal layer and the second metal layer, respectively, the remaining portion surrounding the central portion,

wherein the first metal layer and the second metal layer include one or more selected from the group consisting of silver, palladium, gold, platinum, nickel, tin, copper, tungsten, titanium, and alloys thereof, and

wherein the first ceramic layer is provided so as not to cover a surface of the first metal layer in the first direction, and the second ceramic layer is provided so as not to cover a surface of the second metal layer in the first direction.

18. The capacitor assembly according to claim 17, wherein the shape of the first and second exposed portions in the second direction is defined by the first and second ceramic layers surrounding the first and second exposed portions, respectively.

19. The capacitor assembly of claim 17, further comprising:

first and second external electrodes disposed on the first and second exposed portions, respectively, to be connected to the first and second metal layers, respectively.

20. The capacitor assembly according to claim 19, wherein each of the first and second external electrodes extends along the second direction to cover a portion of two opposite surfaces of the body in the first direction and is in contact with respective portions of the first and second metal layers exposed in the first direction, respectively.

21. The capacitor assembly according to claim 17, wherein a ratio of an area of each of the first and second exposed portions in contact with the first and second metal layers, respectively, to an area of each of the first and second metal layers is less than or equal to 0.7.

22. The capacitor assembly according to claim 17, wherein each of the first and second exposures comprises two or more exposures spaced apart from each other, and a respective one of the first and second ceramic layers is disposed around the two or more exposures.

23. The capacitor assembly according to claim 19, wherein the first and second external electrodes are provided to extend onto two opposite surfaces of the body in the first direction and/or to extend onto two opposite surfaces of the body in a third direction perpendicular to the first and second directions.

24. The capacitor assembly according to claim 19, wherein the first and second outer electrodes each comprise nickel.

25. The capacitor assembly according to claim 19, wherein the capacitor assembly further comprises a plating disposed on the first and second outer electrodes.

26. The capacitor assembly according to claim 25, wherein the plating comprises one or more nickel plating and/or one or more tin plating.

27. The capacitor assembly according to claim 25, wherein the plating layer comprises a first plating layer and a second plating layer, and the first plating layer and the second plating layer are each sequentially formed on the first outer electrode and the second outer electrode, wherein the first plating layer is a nickel plating layer and the second plating layer is a tin plating layer.

28. The capacitor assembly according to claim 17 wherein each of the first and second exposed portions has a rectangular shape, a circular shape, or an oval shape.

29. The capacitor assembly according to claim 17 wherein one or more first exposed portions are disposed on the first metal layer and one or more second exposed portions are disposed on the second metal layer.